The invention relates to a drilling tool for metallic materials, comprising a holder having an axial clamping slot in which a plate-shaped drilling blade is inserted to bear against the base surface of the clamping slot and is clamped against a limb of the clamping slot by means of at least one threaded pin, which is provided with a head and which engages in a bore in the drilling blade and in a bore in said limb of the clamping slot, wherein the center axis of the bore in said limb of the clamping slot is offset relative to the center axis of the bore of the drilling blade and at least one of two mutually facing circumferential edges of the threaded pin and the bore of the drilling blade is bevelled, and further comprising a centering pin which is inserted in the holder and engages in a centering slot in the side of the drilling blade adjacent to the base surface of the clamping slot so as to center the drilling blade with respect to the rotational axis of the holder.
In the case of this known drilling tool (German patent specification 32 04 210 C2) the tolerance range of the nominal width of the centering slot must be so selected that the centering slot exhibits an excess dimension relative to the nominal diameter of the centering pin so as to be able to guide the centering pin into the centering slot. This has the consequence that the drilling blade cannot be precisely centered relative to the rotational axis of the holder or drilling tool. The result is an inexact rotational course of the drilling blade, particularly of its tip.